Seismology and geodesy of the sun: Low-frequency oscillations
- 1 April 1981
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (4) , 1989-1993
- https://doi.org/10.1073/pnas.78.4.1989
Abstract
The hourly averages of the solar ellipticity measured from June 13 to Sept. 17, 1966, are analyzed for indications of solar oscillations with periods in excess of 2 hr nu < 0.5 hr(-1). Nothing significant is found for frequencies nu > 0.1 hr(-1) but for lower frequencies the power spectrum shows a very complex structure containing about 20 strong narrow peaks. The complexity is illusionary. The signal apparently consists of only two frequencies. The complexity is due to aliasing by the window function with its basic 24-hr period, with many observational days missing, and with different numbers of hourly averages for the various observational days. Both signal frequencies are apparently due to odd-degree spherical harmonic oscillations of the sun.Keywords
This publication has 1 reference indexed in Scilit:
- Seismology and geodesy of the sun: Solar geodesyProceedings of the National Academy of Sciences, 1981